1. Field of the Invention
The present invention relates to novel ferrocene derivatives, surfactants containing them and a process for producing organic thin films, more particularly to novel ferrocene derivatives having a structure in which an anion group including alkali metals is contained in the side chain bonded to a ferrocene skeleton; surfactants containing said ferrocene derivatives, and capable of making hydrophobic organic substances including phthalocyanine soluble, and a process for making hydrophobic organic substances soluble using said surfactants and a process of producing thin films thereof.
2. Description of the Related Arts
In general, coloring matters such as phthalocyanine or its derivatives are insoluble in water, and although they are soluble in organic solvents such as chloronaphthalene, dimethylformamide (DMF), tetrahydrofuran (THF) and the like and concentrated sulfuric acid, their soluble amounts are small and the solubility is as small as several milligrams.
Surfactants to dissolve phthalocyanine and the like in water have heretofore been investigated, but a satisfactory one has not been developed yet.
It is reported that functional group-substituted phthalocyanine derivatives can be dissolved in water to some extent with the use of sulfone-based surfactants. The solubility therein, however, is not always sufficiently high and unsubstituted phthalocyanine cannot be dissolved at all.
In connection with water-insoluble polymers, surfactants to make them soluble in water have been investigated similarly as the above, but a satisfactory result has not been obtained yet.
The present inventors' group has previously developed ferrocene derivatives having polyoxyethylene chain as surfactants to make coloring matters such as phthalocyanine or its derivatives, or water-insoluble polymers and the like soluble, and at the same time have developed a process for forming organic thin films by applying so-called Micellar Disruption Method by use of said ferrocene derivatives (PCT International Publication W089/01939).
The present inventors have made extensive investigations to develop a process for improving the abovementioned surfactants, making the oxidation-reduction reaction of ferrocene derivatives in Micellar Disruption Method proceed smoothly, and improving the productivity of organic thin films much more.
As the result, it has been found that the object can be attained by novel ferrocene derivatives having a structure in which an anion group is contained in the side chain of a ferrocene skeleton. The present invention has been completed according to these findings.